Cell Cycle

btrinh's version from 2017-06-15 02:54

Section 1

Question Answer
InterphaseG1, 2, G2
G1 phaseGAP 1: Normal activity, metabolism, prep for S phase
S phaseSynthesis: DNA replication
G2 phaseGAP 2: Similar to G1, except prep for M phase
M phaseMitosis: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis

Section 2

Question Answer
G1/S checkpointFunction: decides whether cell is committed to cell proliferation or not
G2-M checkpointFunction: DNA check/repair, and apoptosis if needed
Describe 2 pathways of non-dividing cells in G1Reversible exit (G0= quiescence); Irreversible exit (differentiate, apoptosis or senecence)
Senescence cells Metabolically active, not dividing due to telomere shortening
What causes a cell to proliferate? Oncogenes, CDK/cyclins activate; tumour suppressors inhibit cell proliferation
How do we determine polidy (n)? # centromeres per Xm type
How do we determine # of copies of DNA? # chromatids per centromere

Section 3

Question Answer
Apoptosis Programmed cell death
What are the two pathways of apoptosis?Extrinsic (cell receptors) or Intrinsic (cell stress/damage)
Extrinsic pathwaysignal transduction for intracellular signal to activate caspases
Intrinsic pathway signal pathway to release cytoC to activate caspases

Section 4

Question Answer
Cancercollection of diseases that are related, caused by mutations
What causes mutations? Increased expression of oncogenes; decreased exp of tumour suppressors
When mutations occur, what can happen? Uncontrolled cell growth/ proliferation (- checkpoints/ + telomerase exp); mutations accumulate (no DNA repair enzymes); resist apoptosis (no caspases)
What makes a benign tumour dangerous? Angiogensis (makes blood vessels for itself) and metastasis (spreads in blood/lymph)